Study On The Temperature Field Characteristics Of Bridge-subgrade Transition In Seasonal Frost Regions

Seasonal frozen soil is widely distributed in China, disease such as frost heaving and thawing settlement easily occurs. Due to the high speed of train, it needs high requirements for smoothness and stability of the line. So the prevention measures of frost heave is very important in seasonal frozen soil area when building high speed railway.In addition, bridge-subgrade transition is an important part of high speed railway line and it plays a special role. It can ensure the bridge and subgrade transition smoothly. In seasonal frozen regions, the change of temperature can cause frost heave of bridge-subgrade transition. Therefore, it is necessary to study the temperature field of bridge-subgrade transition and analysis the distribution characteristics of the temperature field. In order to prevent the occurrence of frost heave and ensure the railway run normally.Harbin-Qiqihar passenger dedicated line is a new high speed railway in Heilongjiang province. The whole line is distributed in seasonal frozen regions. This thesis is based on Harbin-Qiqihar passenger dedicated line project, and then select test section, the main research and results are as follows:(1)First, the field data of bridge-subgrade transition is detected by instrument. This thesis analysis the field data and then summarize the change law of temperature and frost depth.(2)Based on the field data, the temperature field of bridge-subgrade transition issimulated by ABAQUS software. The thesis points out the factors that influence the temperature field variation by analyzing the characteristics of the temperature field. In view of these factors, insulation measures are proposed to prevent the frost heave of bridge-subgrade transition effectively.(3)At last, bridge-subgrade transition with insulation measures is simulated by ABAQUS software, and then compares the results with the common subgrade. Results show that the insulation effect is good for bridge-subgrade transition which has used the insulation measures. It can effectively improve the temperature and prevent the deformation of subgrade which caused by frost heaving in bridge-subgrade transition.The research results of this thesis can provide a reference for the design of bridge-subgrade transition of the seasonal frozen soil area in the future.